| The dissertation consists of two parts.The first part is focused on the study on the analytical methodology based on ratiometric fluorescence for the detection of peroxynitrite(ONOO)and evaluation of the scavenging effect of mitoxantrone to·NO2.The second one presents some preliminary experimental results related to CdTe Quantum Dots-mitoxantrone conjugate and its application in determination of nucleic acids.In chapter 1 of part one,a brief review on the biological active species,ONOO-,is given,conceming its formation,decomposition,reactivity,and its biological significancy, as well as the methods for the determination of peroxynitrite that have been developmented and used in analytical science and bioscience.A systematic review on the theory and application of ratiometric fluorescence are also presented.160 references are cited.The research plan for part one of the present dissertation is given.In chapter 2 of part one,the results of a serie studies on the analytical methodology based on ratiometric fluorescence for the detection of peroxynitrite are presented.This chapter contains three sections.In section one,a study on ratiometric determination of ONOO- using Terbium(Ⅲ) complex as a fluorescent probe is presented.ONOO- decomposes to free radical of nitrite (·NO2)and hydroxyl radical(·OH)on protonation.·OH would react rapidly with terephthalic acid and transfer the latter to a high fluorescence compound,2-hydroxyl-terephthalic acid.Terephthalic acid would sensitize the luminescence of Tb(Ⅲ)through a intramolecular energy transfer manner on coordinating with Tb(Ⅲ).The formation of 2-hydroxyl-terephthalic acid could greatly attenuate the sensitization of Tb(Ⅲ)'s luminescence,thus,an increase in the fluorescence intensity of 2-hydroxyl- terephthalic acid at 430 nm and a decrease of the fluorescence intensity of Tb(Ⅲ)at 545 nm would be observded in the presence of ONOO-.The intensity ratio,F430/F545,was proportional to the concentration of the hydroxyl radical,and thus to the concentration of peroxynitrite.In section two,a ratiometric fluorimetric method for detection of peroxynitrite based on the formation of excimer of pyrene was explored.Tyramine was labeled with pyrene. When dityramine was formed due to reaction tyramine with peroxynitrite,excimer of pyrene would form as a result of the short distance between the two pyrene molecules.The increase in fluorescence of excimer would be observed and,at the same time,the decrease in fluorescence of monomer of pyrene would be measured.The ratio of the fluorescence intensity of monomer(IM)versus the fluorescence intensity of excimer(IE)would have a good response to peroxynitrite.This hypothesis,however,the expected results have not been gotten yet.In section three,a ratiometric synchronous fluorimetric method for detection of peroxynitrite was developed based on the formation of dityrosine.Tyrosine acted as inner reference.The ratio of the fluorescence intensity of dityrosine versus the fluorescence intensity of tyrosine was not affected by instrument parameter and had a good response to peroxynitrite by synchronous fluorescence spectrometry.In chapter 3 of part one,based on the result obtained in section three of chapter 2,a new method was established for evaluation of the scavenging effect of mitoxantrone to·NO2 by fluorescence spectrophotometry.The transformation of tyrosine to dityrosine is mediated by·NO2 produced from ONOO- and and catalized by CO2.The production of dityrosine was attenuated in the presence of mitoxantrone due to the scavenging action of mitoxantrone on·NO2 and,thus the fluorescence produced by dityrosine was reduced.The change of fluorescence had a good response to mitoxantrone.In chapter 4 of part one,the research work of part one was summarized,and the expectation and limitation of this research were given.In chapter 1 of part two,the brief introduction concerning quantum dots and its conjugate are given.Water-soluble CdTe quantum dots were prepared and conjugated with mitoxantrone through electrostatic interaction.Upon this reaction,the fluorescence of QD was quenched.When DNA was added,the fluorescence of QD was increased.A possible mechanism of the interaction was proposed.Thus,a novel approach was developed for detection of DNA.In chapter 2 of part two,the research work of part one was summarized,and the expectation and limitation of this research were given.
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